Electric toaster



R. H. GARDNER ELECTRIC TOASTER May 5, 1953 4 Sheets-Sheet 1 Filed Jan. 6. 1949 INVENTOR. Roland H. Gardner ATTORNEY.

R. H. GARDNER ELECTRIC TOASTER May 5, 1953 4 Sheets-Sheet 2 Filed Jan. 6, 1949 INVENTOR.

Roland 11. Gardner BY XW ATTORNEY.

R. H. GARDNER ELECTRIC TOASTER May 5, 1953 4 Sheets-Sheet 4 Filed Jan. 6, 1949 Fig. 4

INVENTOR. Roland H. Gardner ATTORNEY.

Patented May 5, 1953 GFFWE ELECTRIC TOASTER Roland H. Gardner, North Canton, Ohio, assignor to The Hoover Company, North Canton, Ohio,

a corporation of Ohio Application January 6, 1949, Serial No. 69,501

8 Claims.

This application relates to toasters and more particularly to a thermal timer therefor and specifically a thermal timer of the heat-up type in which the toasting intervals are timed by the time it takes for a thermally responsive element to be heated to a definite predetermined temperature.

Toaster timers of the thermal heat-up type are old in the art but have not been entirely satisfactory because of the difliculty in designing such a timer which will properly time a toasting interval starting with a cold toaster when both the timer and toasting oven are cold, and also properly time quickly following toasting operations when both the timer and toasting oven may be quite hot.

By experiment, it has been found that if a heat-up timer is properly designed to time a first toasting operation starting with a cold toaster the timer will act too quickly for toasting operations following closely upon the first, and that with succeeding quickly following toasting operations toast will be cooked progressively less and less.

Attempts have been made to overcome this tendency of a heat-up thermal timer to overcompensate by-the provision of a secondary thermally responsive element to delay the operation of the main thermostatic element as the timer and toaster as a whole rises in temperature with rapid repeated use.

Those attempts have disclosed that it is unnecessary to change the operation of the timer as the toaster as a whole heats up during the first toasting operation and that for succeeding toasting operations, after the toaster has been heated up, it is necessary that the action of the timer be varied between or during succeeding toasting operations by means responsive to oven temperature in order to avoid the tendency of the heat-up thermal timers to over-compensate.

According to the present invention, the foregoing difficulties are overcome by means of a secondary thermally responsive element which is locked out of operation during the first toasting operation starting with a cold toaster, but which is operative between or during succeeding toasting operations to lengthen the timed interval over that which would otherwise result were the secondary thermostat not present.

According to one modification of the invention the secondary thermostat is locked out of operation during each toasting interval but is free to act between toasting operations. In this form of the invention the toasting interval is fixed 2 at its initiation depending upon toast-er temperature at that time and does not change F u-l p toasting period regardless of in toaster temperature during that period.

According to a second modii vention the secondary thermal ment is locked out of operation first toasting interval star lng wan the toaster cold. For subsequent toasting operations, or when the toaster is hot, the secondary thermally responsive element may change the operation of the timer during the toasting interval as the toaster temperature changes.

Other objects and advantages of this invention will become apparent as the desc. ption proceeds when taken in connection with the accompanying drawings in which:

Figure l is a perspective view of the toaster of this invention;

Figure 2 is a longitudinal cross-sectional View of the toaster of Fig. 1;

Figure 3 is a Vertical sectional view of the toaster of Fig. l on line 3-43 of 2;

Figure 4 is a plan view of the toaster of Fig. l on line 4-4 of Fig. 2;

Figure 5 is a view of the timer downwardly on line 5-5 of Fig. 7 Figure 6 is a fragmentary view oi the latch mechanism of Fig. l in one of its latching positions; and

Figure '7 is a modification of the stop mechanism usable with the toaster of Fig. 1.

This application is an improvement over my copending application, Serial No. filed August 19, 1952, which application is a reissue application of my Patent 2,585, 55 granted February 12, 1952, on an application Serial No. 789,867, filed December 5, 1947.

Referring to the drawings, the reference rillmeral 10 represents a base for the toaster of this invention which may be made oi": any sutable insulating material such as a phenolic condensation product or hard rubber. The base has a ledge H upon which a supper Mg plate is mounted and a second ledge it which receives the lower edge of an appearance housing it; having bread receiving slots is in its top.

Attached to the front of the base ill is a plate l6 which carries a frame, generally indicated by the reference numeral ll, upon which a bimetallic timer I8 is mounted. Frame ll comprises a rigid end I9 (Fig. 5) and an end 2t pivoted to the frame ll at 2i. Ends Ii} 293 have recesses 22 and 23 respectively which receive the opposite ends of the time l8. An eye bolt is pivoted ion oi" the inresponsive eleto the frame I l at 25 and extends through an opening in the pivoted end 28. The free end of the bolt 24 is threaded to receive a nut 26 acting against a follower 21 which contacts one end of a compression spring 28, its opposite end abutting against the pivoted end 20 of the frame ii. The nut 28 comprises a factory adjustment whereby the proper tension may be applied to the timer I8.

As shown in Fig. 5, one end of a link 29 is secured to the central portion of the timer I8, its,

opposite end being pivoted at 38 to an arm 3!, one end of which is pivoted to the frame H at 32 and its opposite end carries a lug 33 which extends through an opening in the side of the frame I? for a purpose which will be explamed hereinafter.

Supported on plate I2, above the frame I1, is a vertically extending U-shaped bracket 34 having it bight portion secured to the upper side of the supporting plate I2. Pivoted to a pin 35 extending through the upwardly extending legs of the bracket 34 is a latch lever generally indicated by the reference numeral 38. The latch lever 35 comprises a plate 3? connecting a pair of legs 38 and 89 having openings to receive the pin 35. The leg 38 is extended downwardly at 48 through an opening in the supporting plate I2 into a position in front of the lug 33 of the lever BI as shown in Fig. 2. The leg 39 is extended outwardly at 49 and bent rearwardly to form a hook 42 (Fig. 6') positioned below the pivot pin 35. The latch lever 36 is biased clockwise as viewed in Fig. 6 (counterclockwise as viewed in Figs. 1 and 2) by a spring 4|, the set screw I9! and plate 43 carried by the bracket 34 forming a stop.

A second latch lever, generally indicated by the reference numeral 45, is also pivoted to the pin 35. The latch lever 45 is also of inverted U-shape and has a pair of legs 48 and 41 extending downwardly below the pivot pin 35. The leg 47 is extended laterally at 48 (Fig. 3) and the leg 46 has a lug 49 extending rearwardly toward the toasting oven as shown in Figs. 1 and 2. The latch lever 45 is also biased clockwise as viewed in Fig. 6, counterclockwise as viewed in Figs. 1 and 2 by a spring 59, the set screw BI and lug 52 formin a stop.

A carriage plate 54 carrying bread racks 53 is mounted for vertical reciprocation on vertically extending guide rods 55. At their upper ends the guide rods 55 are secured to a bracket extending forwardly from the front wall 56 of the toasting oven while at their lower ends they are secured to the supporting plate I2. A pair of arms 51 and 58 are pivoted to the rear wall 59 of the toast oven and extend forwardly along its side wall 68 and BI. The arms 51 and 58 are secured to the carriage plate 54 by pins extending through slots 62 so that the carriage plate 54 can mov vertically as the arms move about their pivots. At their forward ends the arms and 58 are extended forwardly through a slot 63 in the appearance housing I4 to receive a manipulating handle 64. A tension spring I98 is anchored at its upper end to the rear oven wall 59 and its lower end to the arm 57 so as to normally hold the carriage plate 54 and its associated parts in their vertical position.

An arm 95 is pivoted at 63 to the carriage plate 54 and at its opposite end carrie a reversely bent abutment 61 adapted to overlie the lug 49 of latch 45 under certain conditions to be explained hereinafter. The arme65 is normally biased downwardly by a compression Spring 68 acting between the lug 69 secured to the carriage plate 54 and a lug I8 carried by the arm 65. A latch lug II (Fig. 6) is secured to the carriage plate 54 above the arm 65 and has a portion 12 extending forwardly in front of the arm 65 to cooperate with the latches 36 and 45 in a manner which will be explained hereinafter.

Extending forwardly from the arms 65 is a lug 13 which cooperates with a spring arm '74 to press a bridging contact I5 against a pair of fixed contacts 16 carried by the supporting plate I2 in a manner which will be more fully explained hereinafter.

Freely pivoted to the arm 65 near its free end is a link TI (Fig. 2) carrying a roller I8 adapted to overlie a return bent lug 19 carried by the lever 3| and extending through the upper side of the frame I1 and operating in a manner to be more fully explained hereinafter.

Pivoted to the front of the wall 58 at 88 is a downwardly extending arm 8| which extends downwardly through a slot 82 in the supporting plate I2. The arm BI is normally biased forwardly by a tension spring 83 and is adapted to be moved rearwardly in a manner to be explained hereinafter by a link 84 pivoted to the arm 8| intermediate its ends and a link 89 pivoted to the arm 5? at 8'! and having a return bend 88 at its opposite end positioned in a slot 89 in the link 84.

At its lower end the link 8i carries a frame 99 (Fig. 2) extending the full length of the timing bimetal I8. The frame 99 carries an auxiliary heater 9| and the reflector 92 which are positioned immediately in front of the bimetal I8 during timing operations as will more readily appear hereinafter. The auxiliary heater 9! is preferably connected in series with the main heaters 93 positioned in the toasting oven and in series with the fixed contacts 79.

Pivoted at to the frontoven wall 55 so as to be responsive to oventemperature is a compensating bimetal 94 which extends downwardly and faces toward an angle bracket 95 carried by the arm 8|. The bimetal 94 is so made that its lower end bows toward the angle bracket 95 with rises in temperature. At its free end the bimetal 94 carries an angled member 96 which cooperates with the angle bracket 95 as will be hereinafter explained. The member 95 has its inner edge out at an angle with a large notch 97 and a plurality of smaller notches 98 out therein.

In the modification shown in Fig. 7 the angle member 96 has a notch 99 and a smooth cam surface I88 on its inner edge to coact with the angle bracket 95 as will be explained.

The member 98 is provided with a slot I [II which receives the upper end of the lever I92 pivoted to the supporting plate I2 at I83; At its lower end (Figs. 3 and 5) beneath the supporting plate I2 the lever I92 carries a nut I94 which cooperates with a threaded shaft I85 rotatably carried by the base I0 beneath the supporting plate I2. A manipulating knob I86 is positioned exteriorly of the base III for ready manual manipulation of the shaft I95.

Operation Bread is inserted through the slots I5 so as to rest upon the racks 53. The carriage plate 54 is then moved downwardly against the bias of spring I98 by grasping the handle 64 and moving t downwardly. As the carriage plate 54 moves downwardly the lug 13 which extends forwardly from the arm 95 will engage the spring arm I4 aeamcv and move the bridging contact 15 into contact with the fixed contacts it so as to simultaneously energize both the main heaters 93 and the auxiliary heater iii. The lug '12 carried by the carriage plate 54 will move beneath the hook 12 of the latch lever 36 so that the carriage plate 54 and the bread racks 53 will be latched in-lowered position within the toasting oven.

Simultaneously, with the movement of the carriage plate it to downward position, arm 51 will be moved downwardly to permit the links 86 and 84 to collapse as shown in Fig. 1 and permit the spring 33 to move the arm 8| clockwise as viewed in Fig. 1 so as to bring the auxiliary heater 9| and reflector 92 immediatelyin front of the bimetallic timer is to a position determined by contact of the angle member 95 with the inner edge of angle 96. If the toaster is cold, the inner edge of the angle member 95 will engage in the notch 91 or in the notch 9d of Fig. 7 so that the position of the auxiliary heater 9! and reflector 92 relative to the timing bimetal :8 will be fixed for the first toasting operation.

Heat from the auxiliary heater 9! will be radiated directly to the bimetallic element l8 and also reflected thereto by the reflector 92. As the bimetal l8 heats up it will straighten out against the action of the spring 28 until it reaches its dead-center position when it will be snapped to an opposite bowed position from that shown in Fig. 5 by the action of spring 28. This movement will cause the arm 3! to be moved to the dotted line position of Fig. 5. The lug 33 will engage the lower end so of the latch lever 36 to move it counter-clockwise as viewed in Fig. 6 against the bias of the spring ii and move the hook 422 from above the lug 12 whereby the spring its will move the carriage plate 54 and racks 53 upwardly and project the finished toast through the slots 15.

At the same time, movement of the arm 51 to its upward position will cause the links 84 and 86 to move to their dotted line positions shown in Fig. 2 so as to pivot the an 8i counterclockwise and move the auxiliary heater 9| and reflector 92 away from the bimetal I8 so as to permit the bimetal it to quickly cool by air circulating upwardly over the frame I! through the supporting plate 12 and upwardly through the toast oven. It has been found in practice that the bimetal l 8 will cool so as to snap backwardly to its original position within just a few seconds after a timing interval is terminated.

As soon as the arm at is moved to the dotted line position of Fig. 2 the angle member 95 is moved out of contact with the notch 91 of angle member 3 5 and since the bimetal 94 has been heated. considerably during the first toasting operation its lower end will bow outwardly so as to position the first of the smaller notchesSB in front of the inner edge of the angle member 95. In the modification of Fig. '7 the steeper portion of the cam I90 will be positioned in front of the inner edge of the angle member 95.

If a second toasting operation is begun immediately new bread will be inserted and the handle t t moved downwardly as before to move the carriage plate 5% and its associated parts downwardly. If the bimetal i8 is still hot the lug 33 of arm 3i will still hold the latch arm 33, counterclockwise as viewed in Fig. 6 so that its hook d2 will not engage above the lug 12. Also the lug it of lever 3| will be positioned beneath the roller 73 so as to cause the link 11 to hold the arm 65 upwardly against the bias of the spring 68. This wfll prevent the shoulder 61 from coming into contact with the arm 49 of latch lever so that the latch lever 45 will be held in its counterclockwise position as viewed in Fig. 1 against the stop 52 by the action of the spring 50. This will cause the projecting end #8 of the latch lever 45 to move over the lug 12 and latch the carriage plate 52 in downward position. 'It is to be noted, however, that neither the main heaters 93 nor the auxiliary heater t l will be energized because the lug "E3 of arm is held out of contact with spring 71 3. However, the timer I B will quickly cool due to its position beneath the supporting plate l2 isolated from all hot parts of the toaster and the fact that the natural air draft created by the heat of the oven will cause air to circulate upwardly thereover. In practice it has been found that the bimetal [8 will usually cool sufliciently fast to snap to its original position within 10 to 15 seconds after the termination of a toasting operation.

When the bimetallic time it snaps backwardly to its original position at a time when the carriage 54 is locked downwardly by latch the lug 33 of lever 3! will be removed from contact with the lug 4d of latch 36 and the lug is will be simultaneously removed from beneath the roller :8 of link TI. That will permit the spring ii to move the latch lever 38 clockwise as viewed in Fig. 6 to bring the hook 42 above the lug iii. The arm 65 will be simultaneously pivoted downwardly by the action of the spring to bring the shoulder 87 into contact with the arm 39 of latch lever 45 to pivot it clockwise as viewed in Figs. 1 and 2 against the bias of spring to and remove the projection 48 from above the lug '52 of carriage 54 permitting it to move upwardly slightly under the bias of spring iii-8 until the lug l2 engages the hook 42 of latch lever 36. Simultaneously, the lug T3 of lever 65 engages spring arm M to force the bridging contact :5 downwardiy against the spaced contacts ES to simultaneously energize the main and auxiliary heaters as and ill to initiate a second toasting operation.

The toasting oven also being hot when the second toasting operation was initiated as described, the second toasting interval should be shorter than the first. However, it has been found that thermal timers of the heat-up type have the tendency to over-compensate and progressively shorten the toasting intervals beyond that necessary after the first interval if the toaster is used in a rapid sequence of operation. This is due to the fact that the timer itself is also progressively hotter at the beginning of each successive toasting operation with the result that the bread becomes progressively underdone as the toasting operations proceed in rapid succession.

According to the present invention the compensating bimetal 24 is provided to prevent the toasting intervals from being shortened too much after the first. It is constructed so that it will be locked out of operation for the first toasting operation starting with a cold toaster, will lengthen the second operation to a maximum amount and thereafter progressively decrease the amount the operation is lengthened to the end that toast of uniform color may be produced regardless of how fast succeeding toasting operations are initiated.

After each toasting operation the arm iii is pivoted backwardly so that the angle bracket $5 is moved away from contact with the member 93 freeing the bimetal 94 for outward movement of its lower end. In the case of the modification of Figs. 1 to 6, inclusive, a new one of the serrations 98 i moved in front of the angle bracket 95 for each succeeding toasting operation. In the case of the modification of Fig. 7 a new point on the cam surface N39 is moved in front of the angle bracket 95. In either case the compensating action of the compensatin bimetal 9A is locked out for the first toasting operation, is at a maximum for the second and becomes progressively less for succeeding operations. In the case of the modification of Figs. 1 to 6, inclusive, the action of the compensating bimetal at is locked out during each operation while in the modification of Fig. 7 the action of the cam surface Hill moves the auxiliary heater 9! and reflector 92 away from the timer [8 during each toasting operation after the first. The cam Hill is so shaped that the increment of movement of the heater away from the bimetal i3 is greatest immediately after the first toasting operation.

As will be evident, movement of the lower end of the bimetallic element 96 outwardly will interrupt movement of the auxiliary heater!!! and reflector toward the timer [8 sooner than would otherwise be the case so that the auxiliary heater M will be positioned farther away from the timer is and thus lengthen the duration of toasting intervals over what they otherwise would be in response to rises in toaster temperature with rapid repeated use of the toaster.

The length of all toasting intervals may be varied manually in adjusting for preparing dark, medium, or light toast. According to the present invention this is superimposed upon the action of the compensating bimetal 94 so that the compensating bimetal will automatically compensate for rises in toaster temperature whether the manual control is set for light, medium, or dark toast.

In adjusting for light, medium, or dark toast the knob 35 is rotated in one direction or the other. The threaded shaft 105 and nut HM may be threaded either right or left handed. In either case rotation of the knob I06 will pivot the lever I92 about its pivot H13 so as to pivot the bimetal 9 about its pivot 85 and change the relative position of the angle members 95 and 9B which in turn will change the final position of the auxiliary heater ti and reflector 92 relative to the timing bimetal i 8.

From the foregoing it can be seen that this invention provides a thermal timer for a toaster of the heat-up type with a compensating bimetal responsive to rises in oven temperature in which the compensating bimetal is locked out of action during the first toasting interval starting with the cold toaster and thereafter lengthens the toasting intervals, over that which they otherwise 1 would be, a maximum increment for the second toasting interval and progressively shorter increments for succeeding toasting operations.

While I have shown but two modifications of my invention it is to be understood thatthose modifications are to be taken as illustrative only and not in a limiting sense. I do not wish to be limited to the specific structure shown and described but to include all equivalent variations thereof except as limited by the scope of the claims.

I claim:

I. A toaster comprising, a toasting oven, main heaters within said oven, a movable bread carrier within said oven, means for moving said carrier froma receiving position to a toasting position adjacent said heaters, a thermal timer for timing the duration of toasting intervals, an auxiliary heater for saidtimer, means activated as an incident to movement of said carrier to toasting position for moving said auxiliary heater toward said timer and for energizing said heaters, a movable stop positioned to limit the movement of said heater toward said timer, a compensating bimetal having a free end movable in response to changes in oven temperature, said stop being positioned to be moved by movement of the free end of said compensating bimetal, coacting stop means carried by said auxiliary heater moving means and coacting with said stop for preventing movement of said stop when said carrier is in its toasting position, said stop being mounted on the free end of said compensating bimetal and having a plurality of stepped serrations, at least one of which is movable into the path of said coacting stop means between toasting intervals and means actuated by movement of said thermal timer operable to deenergize said main heaters.

2. A toaster comprising, a base, a supporting plate mounted on said base, a toasting oven supported on top of said plate, main heaters in said oven, a bread carrier within said oven mounted for movement from a bread receiving position to a toasting position adjacent said heaters and being spring-biased to receiving position, a thermal timer carried by said base beneath said sup-porting plate forwardly of said oven, an arm pivoted to said oven at its upper end and having its lower end extending downwardly below said plate to a position rearwardly of said timer and being spring-biased toward said timer, an auxiliary heater carried by the lower end of said arm, carrier moving means for moving said carrier from receiving to toasting position, linkage means connecting said arm to said carrier moving means, the arrangement being such that said auxiliary heater is held away from said timer when said carriage is in receiving position and is released for movement toward said timer when said carriage is moved to toasting position, a compensating bimetal attached to said oven at its upper end and extendin downwardly n parallel relationship to said arm, said compensating bimetal being constructed to bow toward said arm with rises in oven temperature and a stop carried by the lower end of said compensating bimetal and extending into the path of movement of said arm, said stop having a sloped edge permitting more or less movement of said arm depending upon the temperature of said oven, means for energizing said heaters to initiate a toasting operation and means actuated by movement of said thermal timer operable to deenergize said main heaters.

3. A toaster according to claim 2 in which said stop has a notch so related to said arm as to prevent movement of said stop by said compensating bimetal during toasting intervals which are initiated when the oven is cold.

4:. A toaster comprising, a base, a supporting plate carried by said base, a toasting oven supported on the top of said plate, a thermal timer supported by said base underneath said plate in front of said oven, an auxiliary heater for said timer supported for movement toward and away from said timer to the rear thereof, a bread carriage in said oven movable from a loading position to a toasting position, manual means for moving said carriage from loading to toasting position, means coasting between said manual means and said auxiliary heater for moving it away from said timer when said carriage moves to its loading position and returning it toward said timer when said carriage is moved to its toasting position, a compensating bimetal element having one end fixedly secured to a Wall of said oven and a free end, a stop carried by the free end of said compensating bimetal for limiting the movement of said heater toward said timer, said stop being so shaped as to vary the final position of said heater relative to said timer with variations in oven temperature, means actuated by movement of said carriage to toasting position operable to initiate toasting operations and means actuated by movement of said thermal timer operable to terminate toasting operations.

5. A toaster according to claim 4 in which said stop is so and arranged relative to the supporting means for said auxiliary heater that said bimetallic element is locked out of action when said carriage is in toasting position.

6. A toaster comprising, a base, a supporting plate carried by said base, a toasting oven supported on top of said plate, an elongated thermal timer supported beneath said plate forwardly of said even, an arm pivoted at its upper end to the front wall of said oven and having its lower end extending below said plate rearwardly of said timer, an auxiliary heater for said timer carried by the lower end of said arm and eX- tending lengthwise of said timer rearwardly thereof, a bimetallic strip pivoted at its upper end to the front wall of said oven and extenddownwardly in substantial parallel relationship to said arm for pivotal movement in a plane parallel to the plane of movement of said arm, a stop carried by the lower end of said strip and extending into the path of movement of said arm to limit forward movement of said arm, of said heater toward said timer and manually actuatable means engaging said stop for pivoting said strip so as to move said stop forwardly and rearwardly relative to said arm in adjusting the toaster for preparing light, medium, or dark toast, means for initiating toasting operations and simultaneously moving said arm against said stop and means actuated by movement of said thermal timer operable to terminate toasting operations.

7. A toaster according to claim 6 in which said strip, stop, and arm are so constructed and arranged as to increasingly limit the forward movement of said arm and heater toward said timer as the temperature of said oven rises.

8. A toaster according to claim 7 further characterized in that said stop is so shaped and related to said arm that said stop is locked against movement during toasting intervals.

ROLAND H. GARDNER.

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